Individuals with spina bifida meningomyelocele and hydrocephalus (SB) have difficulties in neurocognitive functions involving core deficits in timing, attention orientation, and motor control, as well as functional deficits in visual perception, attention regulation, and integration of information/contingency learning (the latter including rule-based problem solving, contextual language, and behavioral regulation). In the past 5 years, this component of the program project has documented core and functional deficits as part of a modal cognitive profile that variably characterizes school-age children. In this proposal, we seek to expand the evaluation of the modal profile and sources of variability to include adults with SB and to link with studies of infants in Project 2 (Early Learning). We propose 5 specific aims in a study of 300 participants with SB and 144 normal controls from 8-52 years of age. Specific Aim 1 assesses core and functional neurocognitive operations: timing ( rhythm discrimination); attention orientation (inhibition of return); visual perception (categorical and coordinate perception); attention regulation (line bisection); and two components of information/contingency learning: rule-based problem solving (number estimation), and contextual language (idiom comprehension). Specific Aim 2 tests a model of core and functional deficits and links them to clinical assessments of outcomes. Specific Aim 3 relates core and functional deficits in SB to moderators of outcome, such as spinal lesion level, shunt history, and brain dysmorphology. Specific Aim 4 studies the stability of neurocognitive functions from childhood into middle age. Specific Aim 5 evaluates whether two neurocognitive functions that deteriorate early in normal aging deteriorate more rapidly in adults with SB. The proposed research adds to the information base of neurocognitive function and brain-behavior relations in SB; provides the basis of more targeted interventions for the neurocognitive deficits of SB; has theoretical relevance to the functions of brain regions such as posterior parietal cortex, corpus callosum, and cerebellum; and provides a research model for other neurodevelopmental disorders with genetic heterogeneity, brain dysmorphologies, and variable expression of neurocognitive deficits.